Combined modification of fly ash with Ca(OH)2/Na2FeO4 and its adsorption of Methyl orange

- Alkali-salt combined treatment of FA by Ca(OH)2/Na2FeO4 was studied.
- FA/Ca(OH)2/Na2FeO4 was used to treat MO wastewater.
- FM2 show large BET specific surface area, pore volume and great affinity for MO.
- The Freundlich isotherm and the pseudo-second-order kinetic model fit the best with the experimental results.